Removal of microbial aerosol using titania/chitosan composites in air conditioning systems

Abstract

The humid environment of the air conditioning system promotes the growth of microorganisms on the filter media. Using filter media with antibacterial properties can solve this problem. As a photocatalytic material, TiO₂ is often added to certain products as an antimicrobial. Chitosan (CS) is an antibacterial substance that can be processed into fibers, so it can be considered as a substitute for polypropylene (PP) fiber, which is currently commonly used as a filter medium. Unlike previous studies, this study used an air duct experiment system to simulate the operating conditions of air conditioning systems, and TiO₂ was supported by CS and PP fiber, respectively. Results show that TiO₂/CS exhibited better filtration and antibacterial properties at a 3% TiO₂ impregnation concentration. When the basic weight of CS is 190 g/m², the filtration efficiency can reach 96.8% with only 6 W ultraviolet, but the pressure drop is only 28 Pa. At the same time, the survival of bacteria on CS filter media is about 60% lower than that on PP and bacterial shedding is decreased by more than 35%. Due to the excellent filtration and antibacterial properties of TiO₂/CS composite, its use in air conditioning systems will be of interest.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Additional information

Funding

This study is supported by National Key R&D Program of China (no. 2016YFC0700500).